Punch press



Sept. 20, 1927; ,773

E. GAUTHIER PUNCH PRESS Filed Dec. 29, 1922 /O I i; 5'

/5 /4 24 2/ /4 V /2 /z 50 a0 I /5 /4 /5 25 -23 W 22f -28 Z;ZZ/971T5r ErnesTGazTlMer Patented Sept." 20, 1927. UNITED STATES 1,642,773 PATENT OFFICE.

ERNEST GAUTHIER, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PUNCH PRESS.

Application flIed'December 29, 1922. Serial No. 609,646.

This invention relates to punch presses and more particularly to improved means for securing the punch or movable die in the reciprocating slide of the press.

.Punch presses now iii-general use, and especially those presses which are of the nclinable open back type, are provided with two studs or screws which secure a removable plate to the front of the press slide, the

' punch or movable die being clamped between the plate and slide by ti htening the said screws. It has been found in practice that considerablepressure 'must be exerted between the plate and slide in order to hold the punch sufliciently rigid and that when requisite pressure is exerted to hold the tool, the press slide is actually warped causmg t to bind'in the gibs in which the slide is'rec1pro' catably mounted. In many cases this binding action isnot severe,enou h to so load the press that its action is rea ily apparent. However, after thepress has been operated for a short time the excessive friction between the slide and gibs will cause these parts to wear to such an extent that the slide fails to'reciprocate accurately. As av result the punch, carriedby-theslide fails to exactly enter its cooperating die, carried by the bolster plate, and the cutting edges of punch and die abrade each other, greatly reducing their working life and causing them to produce inferior work. 1

An object of the invention is to provide a securing means of such construction, for holding the punch or movable die in the slide, that the slide is subjected to no strains or warping when the punch is clamped in position, whereby an accurate reciprocation of the slide is attained and wear on the tools reduced to a minimum.

Other objects and advantages of the invention will more fully appear from the fol lowing detailed description and will be particularly pointed out in the appended claims.

The invention is illustrated in the accompanying drawings in which Fig. 1 is a fragmentary front view of a punch press with the invention embodied therein, and I Fig. 2 is an enlarged fragmentary horizontal' sectional view taken on the line 22 of Fig. 1. J Referring-now to the drawings in detail, 10 represents the frame of a punch press, and 11 a slide reciprocatably mounted between upright members 12 thereof. Mounted on each of the upright members 12 is a gib '13 provided with suitable bearing surfaces 14 which are engaged by suitable registering surfaces 1515 formed on the slide 11. The slide at its lower end and on its front side is cut back as indicated at 16 for the entrance of a clamping cap 17. The slide 11 and the cap 17 are provided with registering depressed portions forming an opening 18 for the entrance of a shank 19 of a punch indicated at 20 which is clamped between the slide 11 and cap 17 by a U-shaped bolt 21, the arms 22 of which project through openings 23 formed at'each side equidistant from the center line of the punch shank 19. The rear side of the slide 11 is provided with a depression 24 which extends between the openings 23 andis shaped so that the greater ortion of the curved, closed end of the U- olt engages therewith clearances 30 however bemg provided to cause a concentration of the clamping force of the U-bolt, the major portion of said force being in a line passing through the center of the tool. By tightening nuts 25 threaded onto the ends of the arms 22 the shank 19 of the punch 20 may be clamped between the cap 17 and the front of the slide with the required pressure with out causing the slide to become sprung or warped, or cause the surfaces 15-15 thereof to bind in the gibs 13 in which the slide is reciprocably mounted.

When studs or screws are used instead of a U-bolt for clamping the punch in place on the slide, the slide is sprung or bowed due to transverse bending stresses applied to it asvthe studs or screws are tightened, these stresses warping the slide about the shank 19 of the punch holder 20 as a. pivot. The bowing of the slide about the shank of the punch holder causes the surfaces 15 15 of the'slide to bind on the surfaces 14 of the gibs 13 with the conse ucntdeleterious results heretofore mentione The present improved clamping means overcomes these difliculties by causing a compressive stress to be exerted through the center of the punch and slide, instead of a transverse bending stress, by reason of the U-portion of the bolt which ties the two arms 21 thereof together and engages the slide diametrically opposite the punch shank.

This construction compensates for any tendency of the shank of the punch to spring the slide which occurs in the use of studs or screws.

What is claimed is:

1. In a press comprising a framework, guideways carried thereby, a slide reciprocablymounted in said guideways, one side of said slide being formed with a convex surface, a tool holding member attached to the opposite side of the slide, cooperating arcuate surfaces of the slide and tool holding member designed to clamp a tool therebetween, and a clamping member engaging the convex surface of the slide and the tool holding member in such a manner that all of the compressive force of the clamping member against said convex surface of the slide is counter-balanced by a diametrically opposed force occasioned by the holding member bearing against the tool.

2. In a press comprising a framework,

guideways carried thereby, a slide recipro- -member against the convex surface of the slide is counter-balanced by a diametrically opposed force occasioned by the holding member bearing against the tool. 7

3. In a press comprising a framework, guideways carried thereby, a slide reciprocably mounted in said guideways, one side of said slide being f ormed with aconvex surface, a tool holding member attached to the opposite side of the slide, cooperating member in such a manner that all of the v compressive force of the closed portion of the U-bolt clamp against the convex surface of the slide is counter-balanced by a diametrically opposed force occasioned by the holding member bearing against the tool.

4. In a press comprising a framework, guideways carried thereby, a slide reciprocably mounted in said guideways, one side of said slide being formed with an arcuate surface, a tool holding member attached to the opposite side of the slide, cooperating semi-circular clamping surfaces of the slide and tool holding member designed to engage opposed equal surface portions of a cylindrical tool shank therebetween, and a U shaped clamping member engaging the arcuate surface of the slide and the outer surface of the tool holding member in such a manner that all of the compressive force of the tool holding member is diametrically opposed to and counterbalances the compressive force of the clamping member against the semi-circular surface of the slide, through the medium of the cylindrical tool shank interposed between and engaged by the 00- operating surfaces of the slide and tool holding member.

In witness whereof, I hereunto subscribe my name this 14th day of December, A. D.

' ERNEST GAUTHIER. 

